The purpsoe of the project is to understand the mechanism of in vitro transformation and in vivo tumorigenesis of cells infected by tumor viruses and exposed to chemical and physical carcinogens. The research at present is to determine: 1) biological markers for cells during transformation and/or acquisition of tumorigenesis; 2) the role of the uptake of nutrients, particular sugar transport during cell transformation and tumorigenesis; 3) expression of tumor virus genomes in cells; and 4) the mechanism of persistent infection of tumor viruses on the host cells.